From: Guenter Roeck linux@roeck-us.net
Add name of functions triggering warning backtraces to the __bug_table object section to enable support for suppressing WARNING backtraces.
To limit image size impact, the pointer to the function name is only added to the __bug_table section if both CONFIG_KUNIT_SUPPRESS_BACKTRACE and CONFIG_DEBUG_BUGVERBOSE are enabled. Otherwise, the __func__ assembly parameter is replaced with a (dummy) NULL parameter to avoid an image size increase due to unused __func__ entries (this is necessary because __func__ is not a define but a virtual variable).
Tested-by: Linux Kernel Functional Testing lkft@linaro.org Acked-by: Dan Carpenter dan.carpenter@linaro.org Cc: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Guenter Roeck linux@roeck-us.net Acked-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Alessandro Carminati acarmina@redhat.com --- arch/powerpc/include/asm/bug.h | 37 +++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-)
diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h index 1db485aacbd9..5b06745d20aa 100644 --- a/arch/powerpc/include/asm/bug.h +++ b/arch/powerpc/include/asm/bug.h @@ -14,6 +14,9 @@ .section __bug_table,"aw" 5001: .4byte \addr - . .4byte 5002f - . +#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE + .4byte 0 +#endif .short \line, \flags .org 5001b+BUG_ENTRY_SIZE .previous @@ -32,30 +35,46 @@ #endif /* verbose */
#else /* !__ASSEMBLY__ */ -/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3 to be FILE, LINE, flags and - sizeof(struct bug_entry), respectively */ +/* _EMIT_BUG_ENTRY expects args %0,%1,%2,%3,%4 to be FILE, __func__, LINE, flags + and sizeof(struct bug_entry), respectively */ #ifdef CONFIG_DEBUG_BUGVERBOSE + +#ifdef CONFIG_KUNIT_SUPPRESS_BACKTRACE +# define HAVE_BUG_FUNCTION +# define __BUG_FUNC_PTR " .4byte %1 - .\n" +#else +# define __BUG_FUNC_PTR +#endif /* CONFIG_KUNIT_SUPPRESS_BACKTRACE */ + #define _EMIT_BUG_ENTRY \ ".section __bug_table,"aw"\n" \ "2: .4byte 1b - .\n" \ " .4byte %0 - .\n" \ - " .short %1, %2\n" \ - ".org 2b+%3\n" \ + __BUG_FUNC_PTR \ + " .short %2, %3\n" \ + ".org 2b+%4\n" \ ".previous\n" #else #define _EMIT_BUG_ENTRY \ ".section __bug_table,"aw"\n" \ "2: .4byte 1b - .\n" \ - " .short %2\n" \ - ".org 2b+%3\n" \ + " .short %3\n" \ + ".org 2b+%4\n" \ ".previous\n" #endif
+#ifdef HAVE_BUG_FUNCTION +# define __BUG_FUNC __func__ +#else +# define __BUG_FUNC NULL +#endif + #define BUG_ENTRY(insn, flags, ...) \ __asm__ __volatile__( \ "1: " insn "\n" \ _EMIT_BUG_ENTRY \ - : : "i" (__FILE__), "i" (__LINE__), \ + : : "i" (__FILE__), "i" (__BUG_FUNC), \ + "i" (__LINE__), \ "i" (flags), \ "i" (sizeof(struct bug_entry)), \ ##__VA_ARGS__) @@ -80,7 +99,7 @@ if (x) \ BUG(); \ } else { \ - BUG_ENTRY(PPC_TLNEI " %4, 0", 0, "r" ((__force long)(x))); \ + BUG_ENTRY(PPC_TLNEI " %5, 0", 0, "r" ((__force long)(x))); \ } \ } while (0)
@@ -90,7 +109,7 @@ if (__ret_warn_on) \ __WARN(); \ } else { \ - BUG_ENTRY(PPC_TLNEI " %4, 0", \ + BUG_ENTRY(PPC_TLNEI " %5, 0", \ BUGFLAG_WARNING | BUGFLAG_TAINT(TAINT_WARN), \ "r" (__ret_warn_on)); \ } \